I. Field
The following description relates generally to wireless communications, and, amongst other things, to communication schemes for wireless communication systems.
II. Background
Wireless networking systems have become a prevalent means by which a majority of people worldwide has come to communicate. Wireless communication devices have become smaller and more powerful in order to meet consumer needs and to improve portability and convenience. Consumers have found many uses for wireless communication devices such as cellular telephones, personal digital assistants (PDAs) and the like, demanding reliable service and expanded areas of coverage.
A typical wireless communication network (e.g., employing frequency, time, and code division techniques) includes one or more base stations that provide a coverage area and one or more mobile (e.g., wireless) user devices that can transmit and receive data within the coverage area. A typical base station can simultaneously transmit multiple data streams for broadcast, multicast, and/or unicast services, wherein a data stream is a stream of data that can be of independent reception interest to a user device. A user device within the coverage area of that base station can be interested in receiving one, more than one or all the data streams carried by the composite stream. Likewise, a user device can transmit data to the base station or another user device. Such communication between base station and user device or between user devices can be degraded due to channel variations and/or interference power variations. For example, the aforementioned variations can affect base station scheduling, power control and/or rate prediction for one or more user devices.
Performance for a wireless communication system may be enhanced by using beamformed transmissions to communicate from the base station to the mobile devices. Multiple transmit antennas located at a base station can be used to form beamformed transmissions. Beamformed transmissions, also referred to as beams, typically cover a narrower area than transmissions using a single transmit antenna. A beam can be considered a virtual sector allowing a virtual six-sector system to be generated from a conventional three-sector system. However, the signal to interference and noise ratio (SINR) is enhanced within the area covered by the beams. The communication system can utilize a fixed or predetermined set of beams. Although the fixed beam pattern can be updated or adapted, in contrast to a beam steering system, the beams in a fixed beam system are not dynamically updated based on individual user devices.
Typically, user devices should be assigned to appropriate beams to optimize channel performance. In addition, the beamforming system can utilize a variety of scheduling techniques based upon spatial, frequency or time divisions. The system should select the technique or combination of techniques to optimize channel performance, and consequently system performance. Thus, there exists a need in the art for a system and/or methodology for monitoring channel quality to optimize selection of beams and transmission techniques.